The work in this repo consisted in refreshing ROMIO to a newer
version: the one from the very last MPICH2 release (mpich2-1.3b1).

Great! I saw there was another MPICH2 release, and I saw a ROMIO patch or three go by on the MPICH list recently. Do you expect there to be major differences between what you have and those changes?

I also see this new release (mpich2-1.3rc1). I am going to report the
modifications and inform the list.

I don't have any parallel filesystems to test with, but if someone else in the community could confirm/verify at least one or two of the parallel filesystems supported in ROMIO, I think we should bring this stuff into the trunk soon.

Testing:
1. runs fine except one minor error (see the explanation below) on various FS.
2. runs fine with Lustre, but:
. had to add a small patch in romio/adio/ad_lustre_open.c

Did this patch get pushed upstream?

This patch has been integrated yesterday in mpich2-1.3rc1 with another
patch in romio/adio/common/lock.c. They will be available very soon in
bitbucket.

Do you mean that we should be returning an error string "**iobaddisp" instead of "MPI_ERR_ARG"?

In MPICH2, they have a file mpi/errhan/errnames.txt that will generate
mpi/errhan/errnames.h making the links between codes
like "**iobaddisp" and the corresponding error string "Invalid
displacement argument".
The error.c program tests the presence of "displacement" in the error
string.